Serena Williams vs. Kaia Kanepi: Score and Recap from 2014 US Open

So far, so dominant for Serena Williams at the 2014 U.S. Open. The two-time defending champion continued her torrid charge for a three-peat on Monday, advancing to the quarterfinals with a 6-3, 6-3 win over unseeded Kaia Kanepi on Monday.

"I finally made a quarter final this year !!!", Serena Williams laughing on court about her Grand Slam season so far. Crowd loves it.

The match took only 65 minutes, as Williams went to work with an aggressive game plan designed to highlight her power advantage over Kanepi.

Spoiler alert: It worked.

Williams hit eight aces and 19 winners against 16 unforced errors in a victory that oscillated between flawless and sloppy. The 17-time major champion has dropped only 17 games through her first four matches—the lowest of any player remaining—and is yet to lose a set. By far the most dominant hard-court player in the world, Williams has now reached at least the quarterfinals in her last seven appearances at the U.S. Open.

The top-seeded American will take on 11th-seeded Flavia Pennetta in the quarterfinals. Pennetta defeated Casey Dellacqua 7-5, 6-2 earlier Monday to earn her third last-eight appearance at Flushing Meadows in as many appearances. The Italian made it to the semifinals last year before losing to Victoria Azarenka.

Seth Wenig/Associated Press

Williams has defeated Pennetta in their last five head-to-head matches, including at Cincinnati last month. The only time Pennetta has defeated Williams came in 2005, when injury forced the latter to withdraw.

It's safe to say Williams looked pretty healthy Monday.

While sometimes struggling with accuracy, she set the tone of the match early with a series of dominant service wins. Williams did not drop a first-serve point in the opening set, her run highlighted by six aces. Kanepi did not get a chance for a break point, while Williams needed to convert only one of her five chances to take the first set 6-3.

Playing in her second career fourth round at the U.S. Open, Kanepi seemed noticeably on edge. Fewer than half of her first serves were in play, and when Kanepi attempted to avoid double faults by toning down the speed of her second serves, Williams took advantage. The Estonian lost eight of her 15 second-serve points in the set.

Broken on her first serve to start the second, it looked like Kanepi was in danger of getting loved out of the arena. But thanks to a combination of mental fortitude and a suddenly struggling Williams, she was able to close the match with respectability.

After plowing through Kanepi with her serves during the first set, Williams noticeably struggled with ball placement as the match went along. She double-faulted three times in the second set, including a rare back-to-back double during what could have been a match-deciding game. Kanepi earned two breaks and probably would have forced a third set if she had been able to keep her own serve.

I may have just witnessed live the worst shot Serena Williams has ever hit. Her overhead smash didn't go more than a foot. #usopen

"She plays really well, she plays incredibly hard," Williams said after the match, per Mike Singer of CBSSports.com. "I said Serena, whatever happens, you're still in doubles."

It seemed that whenever Williams gave up an ounce of momentum, she instantly turned the match back in her favor. The world No. 1 earned half of her points in the second set by breaking Kanepi, who was again done in by her second serve. Williams won 57 percent of her return points to close out the match, including nine of 11 second-chance points.

Those are mistakes no one can afford to make against Williams at Flushing, where she's taken home five championships and gone to three straight finals.

Julian Finney/Getty Images

With the field ahead of her largely bereft of top-tier players, Williams is undoubtedly a favorite to complete the first Grand Slam three-peat of her career. Early exits from third-seeded Petra Kvitova and eighth-seeded Ana Ivanovic left her side of the bracket relatively unimpeded, with No. 7 seed Eugenie Bouchard being the only top-10 player in her way.

In fact, Caroline Wozniacki's victory over Maria Sharapova leaves her and Bouchard as the only top-10 players other than Williams remaining. Wozniacki, who made her first quarters since 2012 on Sunday, established herself as the favorite in the bottom half of the bracket. She'll face 13th-seeded Sara Errani on Tuesday.

What remains to be seen is whether anyone can unseat Williams—or come even close. Williams' second set Monday was one of her few signs of weakness during the first week of the event, and she still only dropped three games. The widespread elimination of elite talent has made the 2014 Open more exciting than in typical years, but it's also left the tournament with an air of inevitability.

Williams is the best player in the world playing on her favorite surface. If her fourth-round win proved anything, it's that perhaps not even she can stop herself from making history.